driver core: make struct device_type.devnode() take a const *

The devnode() callback in struct device_type should not be modifying the
device that is passed into it, so mark it as a const * and propagate the
function signature changes out into all relevant subsystems that use
this callback.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Ben Widawsky <bwidawsk@kernel.org>
Cc: Jeremy Kerr <jk@ozlabs.org>
Cc: Joel Stanley <joel@jms.id.au>
Cc: Alistar Popple <alistair@popple.id.au>
Cc: Eddie James <eajames@linux.ibm.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jilin Yuan <yuanjilin@cdjrlc.com>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Won Chung <wonchung@google.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230111113018.459199-7-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 5 insertions, 5 deletions

diff --git a/drivers/hwtracing/intel_th/core.c b/drivers/hwtracing/intel_th/core.c
index 7e753a75d23b..cc7f879bb175 100644
--- a/drivers/hwtracing/intel_th/core.c
+++ b/drivers/hwtracing/intel_th/core.c
@@ -185,11 +185,11 @@ static struct device_type intel_th_source_device_type = {
 	.release	= intel_th_device_release,
 };
 
-static char *intel_th_output_devnode(struct device *dev, umode_t *mode,
+static char *intel_th_output_devnode(const struct device *dev, umode_t *mode,
 				     kuid_t *uid, kgid_t *gid)
 {
-	struct intel_th_device *thdev = to_intel_th_device(dev);
-	struct intel_th *th = to_intel_th(thdev);
+	const struct intel_th_device *thdev = to_intel_th_device(dev);
+	const struct intel_th *th = to_intel_th(thdev);
 	char *node;
 
 	if (thdev->id >= 0)
diff --git a/drivers/hwtracing/intel_th/intel_th.h b/drivers/hwtracing/intel_th/intel_th.h
index 0ffb42990175..6cbba733f259 100644
--- a/drivers/hwtracing/intel_th/intel_th.h
+++ b/drivers/hwtracing/intel_th/intel_th.h
@@ -205,7 +205,7 @@ struct intel_th_driver {
  * INTEL_TH_SWITCH and INTEL_TH_SOURCE are children of the intel_th device.
  */
 static inline struct intel_th_device *
-to_intel_th_parent(struct intel_th_device *thdev)
+to_intel_th_parent(const struct intel_th_device *thdev)
 {
 	struct device *parent = thdev->dev.parent;
 
@@ -215,7 +215,7 @@ to_intel_th_parent(struct intel_th_device *thdev)
 	return to_intel_th_device(parent);
 }
 
-static inline struct intel_th *to_intel_th(struct intel_th_device *thdev)
+static inline struct intel_th *to_intel_th(const struct intel_th_device *thdev)
 {
 	if (thdev->type == INTEL_TH_OUTPUT)
 		thdev = to_intel_th_parent(thdev);